Cyclic Amphiphilic Random Copolymers Bearing Azobenzene Side Chains: Facile Synthesis and Topological Effects on Self-Assembly and Photoisomerization

摘要

In this article, well-defined cyclic amphiphilic random copolymers bearing azobenzene side chains and pendent carboxyl moieties, cyclic-P(BHME m - co -AA n)s, are synthesized by combining atom transfer radical polymerization (ATRP) with Cu(I)-catalyzed azide/alkyne cycloaddition (CuAAC) "click" reaction and selective hydrolysis of tert -butyl ester. Successful synthesis of the cyclic-P(BHME m-co-AA n)s is fully characterized and verified via conventional gel permeation chromatography, triple detection gel permeation chromatography, nuclear magnetic resonance, Fourier transform infrared, and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. The cyclic topology induces profound effects on the glass transition temperatures, self-assembly behavior, and photoresponsive performance of the copolymers compared with their linear counterparts.